The motor compartment of a vehicle is often configured with an energy absorbing device, sometimes referred to as a crush box, located between a bumper and a longitudinally-extending motor compartment rail (commonly called a mid-rail). The crush box is configured to deform in the event of an impact force from a collision to minimize deformation and energy transfer rearward to the motor compartment rail. While functional, crush boxes are expensive, have a large number of parts (increasing vehicle mass) and require additional handling and installation.
In frontal crash events, the mid-rail plays an important role. However, conventional mid-rail designs have not been efficient for use without crush boxes because the mid-rail is often compromised to accommodate packing requirements of the powertrain and chassis components. Typically, the mid-rail cross-section is reduced, which limits load carrying capacity of the mid-rails. Accordingly, ultra-high strength steel is sometimes used to increase mid-rail capacity. Unfortunately, ultra-high strength steel does not provide a robust axial crush mechanism. That is, it is desirable to control the deformation of the mid-rail in an axial (fore-aft) direction so that the motor compartment rail may deform and absorb energy in a collision situation.
Accordingly, it is desirable to provide a motor compartment rail for a vehicle. Also, it is desirable to provide a motor compartment rail that can be used without the added complexity, mass and expense of a crush box. Additionally, other desirable features and characteristics of the present disclosure will become apparent from the subsequent description taken in conjunction with the accompanying drawings and the foregoing technical field and background.